Electric-lamp switch



(No Model.)

C. G. PERKINS.

ELECTRIC LAMP SWITCH.

No. 392,633. Patented Nov. 13, 1883.

WTNESSES: NVENTR l Ntra Starts artnr erich,

CHARLES G. PERKINS, OF HARTFORD74 CONNECTICUT.

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SPECIFICATION forming part of Letters Patent No. 392,633, dated November 131, 1888.

Application filed July 24, 1888. Serial No. 280,924. (No model.)

To @ZZ whom, it may concern.-

Beit known that l, CHARLEs G. PnRIiINs, a citizen of the United States, residing at Hart ford, in the county of Hartford and State of Connecticut,haveinvented certain new andusefnl Improvements in Electric-Lamp Switches; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art t0 which it appertains to make and use the sani-e.

My invention relates to improvements in electric switches, more especially in switches for electrical incandescent lamps. rlhe construction of my switch is such that breaking of the circuit is accomplished by a sudden movement. This feature my application has in common with others of its class.

My improvements reside especially inproviding means for preventing sparking, such means consisting ot' a pair of spring-contacts supplemented by a third spring-contact. The operation of the switch is such that the Iirst two springs make the initial contactand receive the sparks, while the third spring is pressed slowly into contact and makes good electrical connection.

My invention is illustrated in the accompanying drawings, in which- Figure l is a plan of the lampcircuit provided with my switch. Fig. 2 is a vertical section ofthe same on line xx in Fig. l, and Fig. 3 shows a detail.

Referring to the drawings by letter, A is the base of the lamp-circuit, and B the casi ng thereof. Supported upon the base are insulated posts C and l), which form the socket-terminals and with which the terminals of the lamp co-operate in use. In line with each post is supported a set of springs, which are in the present instance of a triplicate constructure, i'or a reason that will appear hereinafter. G0- ing more into detail, there are three springs, E, F, and G, located near the post C, and three similar springs, H, I, and J, located near the post D. These springs are so arranged on being pressed toward the posts from behind that the two outer ones will first make contact and the inner one afterward. The springs are normally insulated from the posts. They constilamp circuit.

pressed into contact with their corresponding posts and when the lamp is in place, the circuit will be complete, and when they are ont of contact with their posts the circuit will be broken.

As a means for operating the springs either to make or break the circuit, I employ devices attached to a shaft, K, which is supported in the casing 0i' the socket and passes between the two sets of springs. rihe shaft K has a thumb-piece, L, by means of which it can be manipulated. The shaft is held in place by the ring lewhich is pressed between the casing and the ange on the end ot' the shaft. Located centrally on the shaft is asleeve, M,which is provided with a slot, in, through which the pin n on the shaft projects. The slot is large enough to allow considerable play to the pin. The sleeve M is provided with a squared head, and over this head and a part ot' the sleeve is pressed, while in the heated state, a piece of insulating material, O, such as glass or bonsilate. Any good insulating material -will serve the purpose. I prefer to attach it to the sleeve while in the plastic state; but this is not necessa'ry, as I may adopt other means of attachment.

It will be observed that the piece O is of a general elliptical shape,and that when its longest sides are presented to the springs they remain out of contact with the posts. If, however, the piece be turned a quarterrevolution the springs will be pressed against the posts and the circuit completed.

In practice, the turning oi the insulatingpiece O is accomplished by turning the shaft through the medium of the thumb-piece. The turning from the position shown in the drawings to a distance of one-quarter of a revolution is accomplished slowly, the two outer springs on either side of the log iirst making contact with their corresponding post and receiving the sparks, while the middle springs follow and complete the connection. In turning back, however, or in continuing to turn for another quarter of a revolution, the action will be somewhat different. Thus when the insulating-block has been carried until the springs press upon diagonally-opposite corners, then a slight movement beyond this point will put the block under Athe intluence of the springs, which will thereupon throw it so as to break IOO contact quickly, and in that way overdo the or more parts and an independent movable effects of sparking. piece behind the parts,whereby the latter may The advantages arising from providing a be brought successively into contact with the zo supplemental contact-springare apparent; but first-named terminal, as and for the purpose 5 theyareespeciallyimportantin switches where set forth.

the making of the contact is slow, while the 2. The combination,with a circuit-terminal, breaking is sudden, as in the present construcof a corresponding terminal made up of two tion. or more springs and an independent movable 25 It is of course not necessary that the initial piece behind the springs for moving the same Io contact should be made by two springs, as a successively into contact with the iirst-named single spring might receive the spark; but I terminal, as set forth.

prefer to employ two springs for this purpose, In testimony whereof I have affixed my sigso as to minimize the effects of sparking. nature in presence of two witnesses.

Having now described my invention, what I CHARLES G. PERKINS. r 5 claim is- Witnesses:

ALBERT H. WALK ER,

1B The combiuation,witl1 a circuit-terminal,

,'INo. H. Wurm.

of a corresponding terminal made up of two 

